The present invention relates to protective covers, referred to as flange covers, which are employed to protect, seal and provide a more pleasing appearance to the edges of a flange, pinchweld or other raw edges such as are often found on automotive bodies, marine bodies and protective head gear. Flange covers are often also used to support a sealing strip or bubble to seal doors, windows and other apertures.
The prior art includes several patents directed to flange covers and methods by which they can be made. Examples include Japanese Patent Application No. 51-51394, filed May 7, 1976, and the following U.S. Pat. Nos.: 3,177,534, Apr. 13, 1965 to Matthoun et al; 3,371,447, Mar. 5, 1968 to Fuff et al; 3,222,769, Dec. 14, 1965 to LePlac; 3,310,928, Mar. 28, 1967 to Weimar; 3,238,583, Mar. 8, 1966 to Bright; 2,607,091, Aug. 19, 1952 to Dodge; 2,986,793, June 6, 1961 to Bright; 3,159,886, Dec. 8, 1964 to Lynch; 3,167,856, Feb. 2, 1965 to Zoller; 3,167,825, Feb. 2, 1965 to Zoller; 3,638,359, Feb. 1, 1972 to Kruschwitz; 3,165,793, Jan. 19, 1965 to Lynch; 3,706,173, Dec. 19, 1972 to Taylor; 3,766,697, Oct. 23, 1973 to Jackson; and 3,363,364, Jan. 16, 1968 to Cadion.
Although it is known in the art to make a flange cover with retention lips of a lower durometer than the rest of the flange cover, such flange covers have certain deficiencies in flexibility, stability, retention and ease of installation due to the bending characteristics of a structure having a U-shaped cross section with legs and web of a single durometer. Generally speaking, in bending a single durometer cover to fit an inside corner, the web portion is compressed while the leg portion is stretched. Conversely, an outside corner requires compression of the leg portion and expansion of the web portion. High durometer flange covers are strong but also difficult to expand or compress. The lower the durometer of the flange cover, the easier installation becomes because the legs and web are easier to stretch and compress. Also, low durometer retention lips improve the retention of the cover on a flange edge.
Unfortunately, a single durometer flange cover having a low durometer also has a tendency to stretch out of shape and twist in corners during installation. As a result, low durometer flange covers can be difficult to install. Also, low durometer flange covers tend to pull away from corners after installation as they recover from the stretching required during installation.
Wherefore, it is an object of the present invention to gain the advantages of both high and low durometer materials in flange covers. It is another object to provide a flange cover which can be easily installed and will not tend to pull away from corners. It is another object of the present invention to provide an economical and practical process for making a flange cover of the present invention. These and other objects are achieved by the present invention which relates to a flange cover having a generally U-shaped cross section defining a pair of legs and a web and wherein the web comprises a higher durometer thermoplastic material than the legs, each of which have retention lips extending inwardly therefrom for frictional engagement of the flange cover with a flange. The present invention also relates to a method of making the flange cover by extruding a flat, elongated strip having a middle portion of higher durometer than both side portions and then bending the strip along its longitudinal axis to form a flange cover having a U-shaped cross section.